This invention relates generally to carriers for transporting bulky loads in confined areas, and in particular to a multi-directional, self-propelled, straddle-lift carrier capable of negotiating relatively narrow passageways while transporting a long, heavy load.
Industrial trucks are often required to move about in narrow aisles in warehouses and factories. They must, therefore, be very maneuverable in order to handle loads in the manner required. Conventional forklift trucks are generally impractical for this type of operation because of their rather limited maneuverability. Furthermore, even forklift trucks which are more maneuverable, such as that disclosed in U.S. Pat. No. 3,031,024 to Ulinski, are still unsuitable because the load is ordinarily oriented perpendicular to the direction of travel. This problem becomes more acute with longer loads.
Similarly, naval combat vessels generally have relatively narrow interior passageways. One of the current techniques for transporting long weapons aboard such vessels is to utilize manually operated hand-lift trucks. Often two such hand-trucks are employed: one at each end of the weapon container.
Currently, the combined load capacity of a pair of these hand-trucks is about 5,000 pounds. However, the weight of weapons is escalating, and some weapons, such as the TOMAHAWK missile, may weigh up to 7,000 pounds. Manual effort to lift and move such loads is becoming unrealistic.
Powered versions of the end-lifting trucks in some cases have proven impractical because they increase the overall length of the transporter/load combination beyond tolerable limits. Furthermore, controlling coordination of two transporters in tandem could be a relatively complex and costly problem to overcome.
A straddle-lift carrier would seem to be an appropriate answer to the above described requirements. Most such carriers, however, are fairly large in size and thus are impractical for use and storage in areas having limited space. A straddle-lift carrier which could be expanded to carry relatively wide loads, but which could be collapsed for fairly compact storage would be desirable.